George Fischer Thermoplastic Piping Systems
Thermoplastic piping systems have been relied on for decades to convey media, whether it's water for process cooling or hazardous liquids for industrial applications. Corrosion is no longer a problem when choosing the appropriate GEORGE FISCHER PIPING SYSTEMS. The harsh environment within chemical plants and the conveyance of chemicals place high demands on the piping systems in terms of safety, economic factors and subsequent maintenance:
- No corrosion problems;
- Safe and economical solutions;
- Reduced maintenance costs;
- Simple, but high quality installation;
- Worldwide presence;
- Widest range of plastic piping systems.
Plastic pipe dimensions are, by convention, specified by the outside diameter, usually denoted by e. This may be supplemented by stating the nominal inside diameter or DN. Sometimes the pipe wall thickness is specified by the SDR or Standard Dimension Ratio.
SDR = d divided by e.
Where d = the outside diameter (mm)
Where e = the pipe wall thickness (mm)
The pipe size can be calculated as follows:
di = 18.8 √Q1 ÷ v
di = Inside pipe diameter (mm)
Q1 = Flowrate in m3/h
v = Flow velocity, usually 0.5 to 1.0 m/s for suction lines
1.0 to 3.0 m/s for discharge lines.
Δ L = L × Δ T × α
Δ L = change in length (mm)
L = original length (mm)
Δ T = difference in temperature (ºK)
α = coefficient of linear expansion (mm/mK)
Material α = mm/mK ABS 0.10 PE 0.15-0.20 PP 0.16-0.18 PVC-U 0.07-0.08 PVC-C 0.06-0.07 PVDF 0.12-0.18
A rough calculation of pressure loss in straight length plastic pipe can be done using,
Δ Pr = λ × (L ÷ di) × (ρ ÷ 2.102) × v2
Δ Pr = Pressure loss (bar)
λ = Pipe friction factor
L = Length of straight pipe (m)
di = Inside pipe diameter
ρ = Liquid density (kg/m3)
v = Flow velocity (m/s)
For smooth bore plastic pipe: λ = 0.02